1. Field of the Invention
The present invention relates to a bottom bracket and, more particularly, to a bottom bracket of a playpen.
2. Description of the Related Art
A conventional playpen comprises a frame having a plurality of transverse rods and a plurality of upright rods, a plurality of joints mounted on an upper portion of the frame to expand and fold the upper portion of the frame, and a bottom bracket mounted on a lower portion of the frame to expand and fold the lower portion of the frame. However, the bottom bracket is not operated easily and conveniently, so that the lower portion of the frame cannot be folded easily and rapidly, thereby causing inconvenience to the user when folding the bottom bracket and the playpen. In addition, the mediate portion of the bottom bracket is easily sprung upward during the expanding process, so that the rods of the frame are folded unintentionally, thereby causing danger to the user when expanding the bottom bracket.